1. Field of the Invention
Embodiments of the present invention relate to a display device, and more particularly, to a liquid crystal display (LCD).
2. Discussion of the Related Art
The related art LCD devices use an optical anisotropic property and polarization properties of liquid crystal molecules to display images. The liquid crystal molecules have orientation characteristics of arrangement resulting from their thin and long shape. Thus, an arrangement direction of the liquid crystal molecules can be controlled by applying an electrical field to them. Accordingly, when the electric field is applied to them, a polarization properties of light is changed according to the arrangement of the liquid crystal molecules such that the LCD devices display images.
Among these LCD devices, the vertically aligned (VA) mode LCD device has an excellent contrast ratio and a wide viewing angle. The VA mode liquid crystal molecules having an anisotropic dielectric constant of negative value are used for the VA mode LCD device. As a result, when the electric field is not applied to the VA mode liquid crystal molecules, the VA mode liquid crystal molecules are arranged such that the major axis of them is perpendicular to substrates of the VA mode LCD device.
The VA mode transflective LCD device, which is capable of having reflective and transmissive modes, has the advantage of low power consumption. The VA mode transflective LCD device can have a different cell gap in the transmissive region than in the reflective region. Such a device is called a dual cell gap type. However, since a process of fabricating the VA mode transflective LCD device having a dual cell gap type is very complicated, production yield is decreased. Moreover, there is a problem of disinclination because of a step between the transmissive and reflective regions.
To resolve these problems, new VA mode transflective LCD device having a single cell gap in both the transmissive and reflective regions has been suggested. In other words, a single cell gap type VA mode transflective LCD. However, the VA mode reflective LCD device having the single cell gap type has great differences between a voltage-transmittance (V-T) characteristic in the transmissive mode and a voltage-reflectance (V-R) characteristic in the reflective mode.
FIG. 1 is a graph showing a V-T characteristic and a V-R characteristic of a VA mode transflective LCD device having a single cell gap type according to the related art. As shown in FIG. 1, the V-T and V-R curves have different patterns. The V-R curve has a positive slope according to the voltage and has a maximum reflectance value. And then, the V-R curve has a negative slope according to voltage at more than the voltage at the maximum reflectance value. On the other hand, the V-T curve has only a positive slope that crosses the negative slope of the V-R curve. Accordingly, to resolve display brightness problems because of the difference between V-T and V-R characteristics, a complicated driving method, for example, a dual gamma method, is necessary that increases production cost increases.